On the Effect of Some Additions and Calcining Temperature on Reduction of Dolomite by Fe-Si (Study on the Production of Metallic Magnesium by the Reduction Method, 3rd Report)

Abstract

Studying the effects of chloride and fluoride addition and the calcining temperature on the yield of magnesium in the process of reducing dolomite, the following results were obtained: (1) Addition of NaF, NaCl, 3NaF·AlF₃ and CaCl₂ decreases the yield of magnesium, but addition of CaF₂, fluorite, MgF₂ increases it. (2) CaF₂ is more effective than MgF₂ for increasing the yield, but, as a binder of dolomite briquette, MgF₂ is superior. (3) The decomposition temperature of MgCO₃ is higher by 200∼300°C than that in dolomite, but that of CaCO₃, matches the latter. (4) The relation between the calcining temperature and the yield of magnesium shows a maximum near the temperature of 1000°C, and this tendency corresponds well that of the insoluble residue of calcined dolomite leached with 5% acetic acid solution in methyl-alcohol.